It is well known that cold air feels much colder in windy weather than what the thermomete...

It is well known that cold air feels much colder in windy weather than what the thermometer reading indicates because of the “chilling effect” of the wind. This effect is due to the increase in the convection heat transfer coefficient with increasing air velocities. The equivalent temperature in °F is given by (1993 ASHRAE Handbook of Fundamentals, Atlanta, GA, p. 8.15)

where V is the wind velocity in mph and Tambient air temperature in °F in calm air. which is takento a be air with light winds at speeds up to 4 mph. The constant 91.4°F in the above equation is the mean skin temperature of a resting person in a comfortable environment. Windy air at atemperature Tambient and velocity Vwill feel as cold as calmair at a temperature Tequiv. The equation above is valid for winds up to 43 mph. Winds at higher velocities produce little additional chilling effect. Determine the equivalent temperature of an environment at 10°F at wind speeds of 10, 20. 30, and 40 mph. Exposed flesh can freeze within one minute at i a temperature below −25°F in calm weather. Does a person need to be concerned about this possibility in any of the cases above?